Hello French Fries!
While Earth may not seem very unique, being the third planet spinning around one star out of billions that is on a minor suburban cul-de-sac a good drive from the center of town, there are several conditions that have allowed life to flourish on Earth.
First off, Earth is an appropriate distance from the Sun to harness solar energy without being too far away to freeze, and too close to be burn. The Sun provides energy to our ecosystems through photosynthesis, where plants convert solar rays into nutrients.
Secondly, Earth contains an abundance of liquid water. The combination of our distance from the Sun, and the size and energy level of the Sun means Earth has water in a liquid form. Think of how exact our distance from the Sun has to be for water to remain liquid. Below 32 degrees Fahrenheit (0 Celsius), water freezes and becomes solid, while above 212 degrees Fahrenheit (100 degrees Celsius), water evaporates and becomes gaseous. If the Earth’s orbit were only 4,500,000 miles off it’s current distance from the sun (a miniscule amount relative to galactic distances), liquid water would not be sustainable. Water would either freeze or evaporate, and life would be unviable.
Thirdly, we have a star in the Sun that’s just the right size to be able to survive for billions of years at consistent levels of energy emissions. Life does not just pop up overnight, it takes millions to billions of years to evolve and develop. It took 1.1billion years from Earth’s formation for the first instances of life to appear. If a star is much bigger than our Sun, it would burn all it’s fuel in only several million years, while smaller stars don’t emit enough energy to sustain life. Consequently, the size and health of a star is vastly important to allow enough time and energy for life to evolve.
Lastly, plate tectonics are considered necessary to supporting and sustaining life. Plate tectonics recycle nutrients and carbon, by subducting older and spent nutrients into the planet’s core, where heat and pressure converts them back to usable nutrients for life which is then remitted into the environment through volcanic eruptions and lava flows. For this exact reason, the best and most diverse farming regions are in the vicinities of volcanoes. With a solid shell, planets would not be able to recycle nutrients and maintain a consistent level of minerals for the sustainment of life, hence plate tectonics are considered vital to life.
So, there is a very specific set of circumstances that allow life to flourish on Earth, hence Earth is quite unique and special. Without all of these factors happening by chance, as they have on Earth, Life would be inconceivable. The specific conditions for life to occur are quite rare individually, let alone all occurring at once on one planet. Even with all the conditions met, life still requires chemicals to form RNA, and then by chance for RNA to mutate into DNA. This is a very specific and rare feat. However, the Universe is massive with at least 2 trillion galaxies, each one containing billions upon billions of stars. When you compare the odds of the conditions for life occurring to the scale and relativity of the universe, the chance that we are not alone in the Universe is quite high.
Well, that’s it for this week. I wish you all a great weekend! Until next time…
…the ketchup is in the sauce.
